Yeah, after killing eight Pol's Voice with a wooden sword, I decided to go find some hearts and the White Sword before going back, and in the process I came across Level 2.
Spoiler: show
I also played a little of 4th, but I can't get through the first dungeon (4 has boss keys, and I can't find them). The actual combat is much less severe than 3rd, though, so if you're struggling I recommend switching to 4th for a while to calm down.